<?php
class App_Model_Acl extends Zend_Acl
{
    protected static $_instance;

    /**
     * Get acl instance
     * 
     * @return App_Model_Acl
     */
    public static function getInstance()
    {
        if (null === self::$_instance) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }
    /**
     * Reset acl instance
     * 
     * @return void 
     */
    public static function resetInstance()
    {
        self::$_instance = null;
        self::getInstance();
    }
}